Potential of Female Athletes from the Perspective of a Female Coach

The differences between human males and females exist both biologically and sociologically and are known as “sex differences”.Females experience growth spurts 2 years earlier than males, and, subsequently, physical sex differences become prominent owing to female hormones. Therefore, coaches need to fully understand the three conditions that female athletes are susceptible to; these are collectively known as the female athlete triad. From a spiritual perspective, female athletes require a different kind of support than male athletes. For female athletes in other countries, athletic careers following childbirth last longer, and they are assured of work-life balance as athletes. Female athletes are not small male athletes. Thus, similarly nurturing independent female athletes may improve their potential in Japan.


Introduction
In 2013, the Ministry of Education, Culture, Sports, Science and Technology commissioned Juntendo University with a multi-support project. Based on the results of this project, collected across two years of research, the university found three challenges that female athletes are likely to encounter. The first is a physical and physiological challenge, which refers to the physical changes that occur from the junior to senior year of high school, including menstruation. The second is a psychosocial challenge, which refers to issues such as sexual and power harassment and parentsʼ understanding of girls who engage in sports activities. The third is an organizational and environmental challenge, which refers to the male-dominated sports world, which has few positions for females, and the lack of social understanding for females who wish to continue their sports careers after marriage and childbirth. Addressing these three challenges may help female athletes achieve successful careers.

Physical and physiological features of female athletes: what is the female athlete triad?
Physical sex differences exist between males and females."Growth spurts" , characterized by an increase in height during puberty, occur 2 years earlier in females than in males; consequently, females can begin professional training 2 years earlier than males. Moreover, females experience their first menstruation a year after their growth spurt, and subsequently, physical sex differences between males and females become prominently visible.
Hormonal balance is the major factor causing the physical differences between males and females. The primary male hormone is called androgen, and it includes testosterone, dihydrotestosterone, dehydroepiandrosterone, etc. These hormones promote protein assimilation and strengthen muscles. They also break down fat and convert it into energy. Under the influence of these hormones, males grow body hair (including beards), which results in a masculine appearance.
There are two kinds of primary female hormones: estrogen, a follicular hormone, and progesterone, a progestational hormone. These hormones assimilate and accumulate fat to store energy. Female hormones are gradually secreted from the age of 7, and their quantities increase with the beginning of menstruation. Secretion volume approaches a peak in the late 20s that is maintained until the 30s and then begins to gradually decrease; secretion is substantially reduced in the 50s. Actually, the secretion increase start of female hormones is the highest in the late teens to around the 30s, which is the prime period for female athletes, and overlaps with the period when they can easily gain weight and store energy.
Female athletes are often reprimanded by their coaches during this period with harsh words such as"you wonʼt be able to run if you get fat"or"donʼt eat."In 2015, the Japanese Center for Research on Women in Sport (JCRWS) conducted a survey that included 314 female long-distance university runners who had competed in the Japan Inter-University Womenʼs EKIDEN Championship 1) , and 71.7% of these athletes had experienced diet restriction (Figure-1).
As coaches often force female athletes to restrict their diet when they are vulnerable to gaining weight, they may begin to feel guilty when they eat. Coaches seem to understand that females are vulnerable to gaining weight, but they may not understand the nature of this mechanism. Therefore, it is essential that coaches provide guidance regarding nutrition to female athletes.
In 1992, the American College of Sports Medicine defined the liable triad as"disordered eating" , "amenorrhea" , and"osteoporosis" . However, in 2007, disordered eating and amenorrhea were revised to "low energy availability with or without an eating disorder"and"functional hypothalamic amenorrhea" , respectively (Figure-2) 2) . These revisions were a result of the observation that low energy availability is experienced by many female athletes even if they do not fall under the category of disordered eating. However, the mechanism of amenorrhea is limited to hypothalamic amenorrhea; in other words, other sicknesses are considered possible from amenorrhea resulting from other conditions. Thus, amenorrhea must be examined at hospitals early to clarify the cause. The revision in which a normal triangle was converted to a triangular arrow has the most significant meaning as it clarifies that monthly hypothalamic amenorrhea is caused by day-to-day"low energy availability" , and, if left untreated, it may cause osteoporosis (Figure-2). Hypothalamic amenorrhea and osteoporosis cannot be cured only with medical treatment; rather, they can be prevented through optimal energy availability.

Energy availability
Energy availability is defined as the dietary energy remaining after energy expenditure and denotes the energy available for other body functions. When energy availability is too low, physiological mechanisms reduce the amount of energy used for cellular maintenance, thermoregulation, growth, and reproduction 3) . Low energy availability is estimated to be 45 kcal/kg of lean body mass per day; however, the energy availability of 30 kcal/kg of lean body mass is associated with most negative effects 4) .

Menstrual function
Amenorrhea is categorized into primary and secondary subsets: primary amenorrhea is the absence of menarche after 15 years of age and secondary amenorrhea is the cessation of menses for three consecutive cycles after menarche. Oligomenorrhea, menstruation every 35 days or involving fewer than nine menstrual cycles per year, is also considered abnormal. Subclinical menstrual irregularities, such as a luteal phase defect and anovulation, also fall along the spectrum, and it is important to rule them out during the triad screening process 5) .
However, for female athletes, premenstrual syndrome (PMS) and menstruation during competitions may lead to performance impairments even with a normal menstrual cycle. In these cases, the use of low dose estrogen-progestin (LEP) to alleviate PMS and delay the menstrual cycle is effective. Reports show that 83% of the top athletes in Western countries take LEP 6) ; therefore, LEP could be widely used in Japan as well.

Bone mineral density (BMD)
The of BMD spectrum includes osteoporosis and also encompasses reduced BMD owing to its role in increased risk of injury in female athletes with the female athlete triad 2) . It is important for younger female athletes to understand that, in most women, 90% of peak BMD is reached by the time they are 18 years of age and that the greatest level of accrual is between the ages of 11 and 14 years 7) .
A research conducted by JCRWS, which surveyed 314 female university runners, revealed that 45.5% of athletes experienced stress fractures, which accounted for approximately half of the total people surveyed 1) . Among these athletes, fracture was the most common at 17 years of age and the second most common at 16 years of age (Figure-3). During stress fracture, 41.4% had amenorrhea and 26.4% had menoxenia, resulting in a total of 67.8% female athletes having abnormal menstruation (Figure-4). Therefore, stress fractures could be prevented if amenorrhea is treated; thus, amenorrhea could also be considered a sign of a possible stress fracture.
In October 2014, Juntendo University Hospital and Juntendo University Urayasu Hospital established the Womenʼs Sports Medicine Clinic, a specialized outpatient department to treat female athlete triad, to support female athletes.

Psychology unique to female athletes
Canada, a leading country in terms of sports, is working toward implementing country-wide efforts to aid female participation in sports and nurture female coaches. Canadian Sports for Life presented three factors explaining why few females donʼ t participate in sports: 1) the lack of female athlete role models; 2) the tendency of parents to not allow their daughters to play sports for fear of injury; and 3) the fact that even if female athletes are successful, they do not receive equal appreciation as their male counterparts. Therefore, it is important for parents and coaches to take an approach that would ensure that female athletes feel more confident.
The imposter syndrome is a psychological state in which diligent and competent females are vulnerable 8) and in which, despite achieving great results and receiving high evaluation, they believe that they have less ability and expertise as compared with what other people perceiveand that they are just pretending to be skilled and defrauding people. When female athletes are successful, they tend to think that their success is a result of a fortunate coincidence or their coachʼs efforts, and they continue to worry about failure. Therefore, it is important for coaches to be aware that female athletes often underestimate themselves. They should also take care to ensure that they do not force their views on female athletes; instead, they should listen to what the female athletes have to say and allow them to reflect on their own performance.

Work-life balance of female athletes: post-delivery training
Independent female athletes who understand the conditions of their own mind and body and are able to self-manage can maintain a work-life balance and therefore continue their athletic career over a long period of time. Many athletes who are also mothers continue their sports careers in countries outside of Japan.
Koikawa evaluated post-delivery training of 10 elite runners 9) and found that the return group, which includes athletes who returned as top athletes after childbirth, continued exercising until immediately before delivery (1.00±0.58 days); however, the non-return group, which includes athletes who did not return as top athletes after childbirth, quit exercising 210 days prior to delivery. Moreover, the return group resumed training 50.9 days after delivery while the non-return group did so 163.3 days after delivery. This research suggests that the return group exerted competitive power in training post-delivery because they had the ability to evaluate their own physical condition.

Conclusion
Women are not Men; Children are not Small Adults. This review clarified that it is important to take a different approach toward female athletes based on physical, psychological, and environmental perspectives. Coaches and family members should understand the challenges that female athletes are likely to encounter and offer support to nurture them to become independent individuals. Moreover, independent Japanese female athletes will be capable of advancing in their careers. Thus, an increase in the number of independent female athletes may lead to increased opportunities for Japanese female athletes.